Strap joint-forming mechanism



July 7, 1953 w. c. CHILDRESS E'I'AL smp JOINT-FORMING MECHANISM 2Sheet's-Sheet 1 Filed June 15, 1950 Patented July 7, 1 953 i Ericsson,Chicago, Ill., assignors to Signode Steel Strapping Company, Chicago,111., a corporation of Delaware Application June 15, 1950, Serial No.168,196

7 Claims.

. I .-,1 V I 1 Our inventionrelates to strap joint-forming mechanism, oras it is rather generally' termed, sealing mechanism. Themechanism isespecially adapted for producing joints between overlapping portions offlat or ribbon like metallic strapping,

which is usually subject to considerable tension,

and a joint-reinforcing sleevelike seal. Such strapping is. employed inavariety of ways in reinforcement of boxes, packages and bundles,

and of aggregates or groups of such objects, containing or consisting ofa wide diversity of merchandise. J,

One well knownand extensively used joint for this purpose is produced byshearing, inwardly from their edges, the adjacent or juxtaposedlongitudin'al. margins of overlapping strap portions and the sleevelikeseal to form pairs of slits that extend a short distance inwardly fromthe margins and define tongues in both the overlapping portions and theencompassing seal, each tongue, defined by a pair of such slits, beingdisplaced or offset laterally-out, of the normal plane of. strap andseal to cause edges of strapping and seal at opposite sides of slits tolie in planes that interward the thing or things being bound by the tosome objection.

.ofother boxes or bundles.

strapping so far beyond the plane of the body, of the joint as to causesuch joints to be subject"; For example, the tongues have projectedsufliciently'to raise the joint and cause it to interfere with thesliding of boxes or bundles upon or against each other and tocatchl'.obstructions, such as the joints. or the strapping j This may subjectjoints to sudden strains caused by shock in tran j sit or in handlingwith liability of rupture. And

the tongues have protruded sufficiently farto indent and mar theunderlying surfaces or edges of superposed bundles or the constituentsof bun? dles. This last phenomenon is particularly ob; jectionable wherethe boundbundles are of relativel delicate or easily dented and marredmatee,

rial such, for example, as sheets of tin plate and' sect. Thus, adjacentlayers of strapping and seal 1 on opposite sides of a slit are caused toabut each other with abrupt opposing edge-to-edge interlocking shoulderswhich resist relativelongitudinal movement of theoverlappingv portionsof.

an effective tension-resiststrapping and create ant joint.

The most feasible if not the necessary pro- I duction of such jointsrequires mechanism which, upon a single operation and essentiallysimultaneously will produce both completeor true marginal slits throughboth the seal and the strap- 1 ping and also the necessary offsetting ofl the tongue formed and definedby the slits to insure that adjacentsheared edges of both strapping and sleeve on opposite s'id'esoftheslits lie in abutting shoulders. strap portions and both layers ofthe sleeve are crossing planes so as to form theedge-to edge If both ofthe overlapping not sheared or cut entirely through the ofisetting willmerely bend the metal and only curved rather than edge-to-edge shouldersand.

metal joints will result Heretofore, however, in

orderv to insure that both the seal and strapping are actually out orsheared through, rather than merely bent, and sufficiently offset toprovide insheets of thin steel currently used in automobile"' bodies andfenders. The principal object of our invention is to pro-,.: vide ajoint forming or sealing mechanism that. will produce joints of thesheared and offset, tongue type which are as strong as those heretoforeproduced but wherein the tongues do not protrude to such anobjectionable extent. Another object is to, provide a simple and ef-ffective tool or machine for producing joints com parable in strength tothose heretofore known but wherein the projection of the offset tongueis reduced. I A further'object is to provide amethod for, producingsuchjoints. Our invention will, be illustrated and explained as embodied ina hand operated sealing tool al-' though, as will be readilyappreciated, the mode of operation and the essential mechanism can beperformed by and incorporated in power-op erated machines.

' Other objects and advantages willhereinafter and finally retract orpull back the tongues to;

reduce the amount they protrude from the fin i ished joint, without,however, detracting from the strength and effectiveness of the joint. j:

A typical embodiment of our invention incorporated in a simple handoperated sealing tool offsetting mechanism at the completion or the:

slitting and offsetting operation;

Fig. 6 is a View similar to Fig. 5, showing the relation of the foldingjaws and the slitting. and,

oifsetting mechanism at the completion of a joint forming operation,when the tongues of the joint have been retracted;

Fig. 7 is. an enlarged View of merely the tips r,"active portions of thefolding. jaws and the slitting and offsetting. mechanism in the three.positions shown, for. the entire tool, in Figs. 4, 5.

and 6; and

'Fig. 8' is a perspective of one edge of. a joint, showinghow the.marginal edges. of the SIEQVQ-r.

like seal and the overlapping strap portions are sheared and theintervening tongue is. offset to insure the necessary crossingedge-to-edge shoulder abutment and then the tongue, is re,- tracted toreduce. its protrusion.

Referring first to Figs. 1,".2. and 3, the specific. hand operable toolillustrated includes a head The inner ll'lfandv a pair of handles i land I2. en'dfof handle I2 is located'between and assists in'the spacingof a' pair'of headside plates i3 and HI and is rigidly attached theretoby a pair of'bolts l5. Handle between side plates [3 and i l on a pivotbolt Head sideplates l3. and M are further retained in proper. spacedrelation by a pair ofjaw pivot pins l1 and apair. of movement-directingand 'stop pins l8. duced diameter where they project into side plates I3and l iso. as to provide side-platespacing shoulders l9 and 20, as shownmost clearly in Fig. 3 and the entire head assembly is clamped togetherby the bolts i and I6 and their respective nuts 2 I,

Pivotally connected to jaw pivots ll between the side. plates are a pairof complementary seal-folding jaws 25, each of which has three laterallyspaced inwardly pointing hooklike tips 26; 2! and 23. The three tips ofone jaw confront corresponding tips of the other jaw and each has'aninwardly opening depression or recess 29 which lies opposite a likeopening or 'recess. in. the corresponding tip of the other jaw. Theconnection between each folding jaw 25 and its pivot pin I! is made witha tight. bearing fit so that each jaw may oscillate about its pivot pinwithout other relative movement between jaw and pin.

The rear ends and confronting inner faces of foldingjaws 25 are providedwith a pair of par allel slots. 35 and 36. in which, as will be latereirplained, notching and offsetting blades .39. slid.-

ably andpivotally fit. By means of a toggle pin.

arms rear. of each folding jaw 25 is connected to'one end of a link 42,the. other ends. of the two links being connected to 'a guiding andnotching blade actuating pin it. Pin 46 is connected to. handle H bymeans of a pair of links and a. pin 48. The opposite ends of pin 45 H.is pivotally mounted.

All four of these pins are of re are flattened to form a pair of keys49, each key fitting into a slot or keyway 5il5l formed in the innerface of side plates l5 and 14, respectively, midway between andperpendicular to a line intersecting the axes of the two pivot pins i1.Thus it will be understood that as handle. H is moved between. aposition such as indicated in Fig[ 4 to a positionsuch as indicated inFig. 6, the toggle connection formed by pin 43, links 41, pin 46, links42 and pins 4! will swing the folding jaws 25 from open position toclosed position and the flattened key ends of. guide pin 4% Will-travelfrom near the top of guides 5i) 5| toward the bottom thereof; and thatthereafter reverse movement of handle II will return the folding jawsfrom closed to open position.

'Each of the previously mentioned notching and oifsetting blades 39 hasa hole 653 through which the corresponding jaw pivot pin i7 looselypasses, and near the rear. upper endv eachblade. is provided with anoutwardly opening recess. or. slot.

6| which slidably accommodates a block 'fizjthat has a. bearing fit uponthe corresponding pin l lif Also each blade 39 has on .its upper outeredge.

an angular cam surface 53 which bears against and rides along thecorresponding guidepin I 8. And further each blade. 39. has. along itsinner upper edge a rounded cam surface'65 and along its longitudinalinner edge two merging angui larly related surfaces 66-61., Of these,the sur-. face 55 may be considered as an extension of the cam surface65. carried with a bearing fit upon centering pin llfi. each roller.lying between and in a plane of two' opposing n'otchingand'oifsettingbladesand in a position to engage cam surfaces. 65.'6-B. -E 1. of:

. both blades.

A chair or' anvil l5 lies betweenthefolding jaws l5 and the'notching andoffsetting blades- 39, 'being'slotted to accommodate the notching'blades, and is retained in place by trunnions 16 which project intoholes in the side. plates: l3. and I4. w Y

In operation handle I l is. swung to separate. it from handle I2 to openthe tool for application to the work. In this condition, as shown inFig.

4, the tips of both sealing jaws 25 and the tips of the notching andoffsetting blades 397 are fully separated and the notching blades areretracted; If the joint between the overlapping strap por tions and 8|is to be reinforced by a sleeve 82 of the flange type, the jaws and thenctching and offsetting blades are now open suiflciently to enable thetool to be appliedwith the chair'or anvil 15 againstthe sleeve backplate 82m) and the. sleeveflangesflflb) flanked by the jaws and notchingblades as shown in Fig. 4 with the shear ing edges and offsettingshoulders of each notching blade separated some distance from thelateral outer corners of the reinforcing sleeve 82 as shown in Fig, 4and as indicated by the full lines. 72 of Fig. '7. Now, with the toolapplied to the A pair of. rollers l9, are

' linkage 4l4642 between the handle I! and folding jaws 25 causes therear ends of jaws 25 to be separated and the hooklike tips 26 toapproach, as previously explained; and the movement of rollers betweenand over the rounded cam surfaces 65 cause the tips H of the notchingand offsetting blades'39 to approach each other.

These initial approaching movements of the folding jaws 25 and of thenotching and offsetting blades 39 bends the sleeve flanges 82 (b)inwardly and'rearwardly to cause the sleeve to encircle the overlappingstrap portions 80-8l and to clamp the strap portions and encirclingsleeve tightly back against anvil 15. As soon as the rollers 10 enterupon the straight portions 66 of the cam track, these portions thenbeing parallel, further outward movement of the top ends of the bladesis' not forced and in fact is inhibited by the pins [8. The notching andoffsetting blades are therefore pushed straight downwardly by the blocks62 acting in the slots 6| inasmuch as the blocks have V a considerabledownward component of movement, they being well beyond the pivot pins I!at this point in their travel. Also the angle made by the slots 6i withthe vertical can be such as to give just the desired degree of relativemovement between the jaws and blades. At the end of travel of thehandles in the closing direction therefore the strapping is tightlywrapped in the seal, the notches are formed, and the tongues are welloffset downwardly.

As the handles are pulled apart the 'jaws immediately start theirretracting movement by swinging outwardly. During the early portion ofthe return travel of the handles the notching blades are pulledapproximately straight upwardly since rocking movement is prevented bythe rollers 10 between the relatively parallel cam surfaces 66. Thelower edges of the tongues are therefore caught by the inwardly directedtongue These horns thereforeretracting horns I1. pull thetonguesstraight backwardly until the rollers 10 emerge'from theapproximatelypar'allel portions 66 of the cam surfaces of the blades onto the sharply outwardly flaring portions 85,. When the flared'portions65 of the cam surfaces are reached, the notching and offsetting bladesare permitted to pivot inwardly'at the top-and this movement is forcedby the block 82 being brought against the ends of the slots 6!. Thisrocks the retracting horns ll outwardly until they,

clear the edges of the tongues; With slight additional'opening' movementof thehandles the tool can be removed from the joint. I

From the above description of one embodiment of our invention, it willbe seen that the seal is automatically tightly wrapped about thestrapping, strapping and seal are sheared and offset a considerabledistance below the plane of the strapping so as to insure good angularlyopposed sheared surfaces, and that thereafter with opening movement ofthe tool, the tongues are reonly slightly below the rectly because ofthe danger of insufficient shearing action taking place with this smalldegree of a pair of tongues on each'side of the oflset. Furthermore, allof this is accomplished by the operator in a natural manner so that anop-'- erator need not be taught any different technique when firstintroduced to the use of this novel;

sealing tool.

Having described our invention, what we claim" 7 as new and useful anddesire to secure by Letters Patent of the United States is:

l. A. tool for producing a'joint between over lapping portions ofmetallic strapping and an encircling metallic reinforcing sleeve,comprising a pair of spaced side plates, a pair of pivot pins held byand bridging between said side plates, a pair of folding jaws, each jawbeing pivotally mounted mom of said pivot pins,said jaws hav-{ ingconfronting hooklike tips which approach each other to clamp the strapportions and sleeve when said jaws are oppositely rocked about saidpins, a pair of shearing and offsetting blades,-

each blade being loosely mounted on one of said pins by means of anopening therein substantially larger than said oin so that said bladeand the.

jaw mounted on said same pin may move longitudinally relative to eachother, an operating linkage pivotally connected to said jaws for rock-'ing said jaws about said pivot pins, means inf-J eluding cam surfaces onsaid blades and a mem-. ber engageabl-e therewith carried on saidlinkage to rock said blades about said pivot pins, and

means holding said side plates in place.

2. A. tool for producing a joint between'overei lapping portions ofmetallic strapping and an encircling metallic reinforcing sleeve,comprising a pair of spaced side plates, a pair of pivot pins held byand bridging between said side plates, a; pair of folding jaws, each jawbeing pivotally mounted on one of said pivot pins, said jaws beingadapted to clamp the strap portions and sleeve when oppositely rockedabout said pins, a

pair of notching and offsetting blades, eachblade having anopeningtherein substantially larger.

than said pin through which said pin projects to mount the blade thereonand so that said blade and the jaw mounted on said same pin may havenected to said jaws for rocking said jaws about said pivot pins, a bladeengaging means on said link-, age and cooperating means on said bladesadapted to be engaged by said blade engaging means to rock said bladesabout said pivot pins to bring "said blades into notching and offsettingposition,

and a lost motion connection between said link- ,age and said blades tomove said blades longitudinally-relative to said jaws and to rock saidblades from notching and offsetting -position,, whereby when saidlinkage is moved in a first direction said blades and jaws are rockedtogeth er to grasp the strap edges encircled by the sleeve, andsubsequently said blades are moved primareily longitudinally relative tosaid jaws while said jaws hold the strap and sleeve to notch thestrapand sleeve and to offset portions thereof a predee termineddistance, and when said linkage moved in the opposite direction saidbladesare retracted primarily longitudinally to return the offsetportions apart of the offset distance, and

place.

3. A tool for producing a joint'between overlapping; portions; Qif:metallic and, anv on circling metallic reinforcing sleeve, comprf.,,ingapair of spaced side plates, a pair of pivot pins held,

mounted on one of said pinsby means of an opening therein substantiallylarger than said pin so that said blade and t e jaw mounted on saidsame, pin may move longitudinally relative to each other, said bladeshaving confronting booklike tips for grasping the edge of the strap portions encircled by the sleeve when said blades are rocked toward eachother, a movable operating linkage pivotally connected to said jaws forreciring, said jaws about said. pivot pins and connected to said bladesfor moving said blades longitudinally and about said pivot pins, cam mans on said blades and a cooperating member on linkage andmovable-therewith to reel: blades about said pivot pins, whereby whensaid linkage is movedin a first direction said blades and jawsareroclied together to grasp the strap edges encircled by the sleeve andsubsequently said blades are moved primarily longitudinally relative tosaid jaws while said jaws hold the strap sleeve to notch the strap andsleeve and to offset portions thereof a predetermined distance, and whensaid linkage is moved in the opposite direction said blades areretracted primarily longitudinally to return the offset portions a partof the oifset distance, and subsequently said jaws and said blades arerocked away from each other to release the strap and sleeve, and meansholding said side plates in place.

l. A tool for producing a joint between overlapping portions of metallicstrapping and an encircling metallic reinforcing sleeve, comprising apair of spaced side plates, a pair of pivot pins held by and bridgingbetween said side plates, a pair of folding jaws, each jaw beingpivotally mounted on one of said pivot pins, said jaws being adaptedtoclamp the strap portions andsleeve when oppositely rocked about saidpins, a pair of notching and offsetting blades, each blade being looselymounted on one of said pins by means of an opening therein substantiallylarger than said pin so that said blade and the jaw mounted on said samepin may move longitudinally relative to each other, means held by saidside plates for limiting pivotal movement of said blades so that saidblades are then constrained for longitudinal movement, said, bladeshaving confronting hcoklike tips for grasping the edge of the strapportions encircled by the sleeve when said blades are rocked toward eachother, a movable operating linkage pivctally connected to said jaws forrocking said jaws about said pivot pins and pivotally and slidablyconnected to said blades for moving said blades longitudinally and aboutsaid pivot pins, cam means on said blades and a cooperating member onsaid linkage and movable therewith to rock said blades about said pivotpins, whereby when said linkage is moved in a first direction saidblades and jaws'are rocked together to grasp the strap edges encircledby the sleeve and subsequently said blades are moved primarilylongitudinally relative to said jaws while said jaws hold the strapsleeve to notch the strap and sleeve and to offset portions thereof apredetermined distance, and when said linkage is moved in the oppositedirection said blades are retracted primarily longitudinally to returnthe, Ofiset portions, a part of the offset, distance, and subsequentlysaid jaws andsaid blades are rocked away. from. each other to, releasethe strap and sleeve, and means holding said side,- plates in place.

5., A tool for producing a joint between over lapping portions ofmetallicstrapping and, an, encircling metallic reinforcing sleeve,comprising a pair of spaced side plates, a pairof, pivot pins,

held by and bridging betweensaid sideplates, a.

tive to each, other, first cam means on said bladesy a pair of pins heldby-said side plates and-engageable with said cam means for guiding saidblades in pivotal and longitudinal movements, said bladeshaving-confronting hooklileetips for grasping the edge of the strapportions encircled by the sleeve when said blades are rocked towardeach, other, a movable operating linkage pivotally connected tosaid-jaws for rocking said jaws about said pivot pins and'pivotally andslidably connected to said; blades for moving said blades longitudinallyand about said, pivot pins, second cam means on said blades and acooperating member on said linkage andmovable therewith to rock saidblades about said pivot pins, whereby when said linkage is moved in afirst direction said blades and jaws are rocked together tograsp thestrap edges encircled by the sleeve and sub sequently said blades aremoved primarily'longitudinally relative to said jaws while said jawshold the strap sleeve to notch the strap and sleeve and to offsetportions thereof a predetermined distance,-and when said linkage ismoved in the opposite direction said blades are retracted primarilylongitudinally to return the offset portions part of the offsetdistancaand subsequently said jaWs and said blades are rocked awayfromeach other to release the strap and sleeve, andmeans holding said side,plates in place,

6. In a tool for producing a joint between overlapping portions ofmetallic strapping, and an encircling metallic reinforcing sleeve,having a pair of spaced side plates, a pair of pivot pins held by andbridging between said side plates,

, a pair of folding jaws, each jawbeing pivotally' mounted on one ofsaid pivot pins, said, jaws having confronting hook-like tips whichapproach each other to clamp the strap portions and sleeve when saidjaws are oppositely rocked about said pins, an operating linkagepivotally connected to said jaws for rocking said jaws about said pivotpins, and means holding said side plates in place, the improvement whichcomprises a pair of shearing and offsetting blades, each blade beingloosely mounted on one of said pins by means of an opening thereinsubstantially larger than said pin so that said blade and said jawmounted on said same pin may move relative to each other, a bladeactuating means on said linkage means, and cam means on said bladesadapted to be engaged by saidblade actuating means as said linkage meansis operated to pivot said blades to; bring them into shearing andofisetting position, stop means limiting such pivotal movement of saidblades, and means connecting said linkage mechanismto saidbladestomovesaid bladeslon:

gitudinally relative to. said jaws to shear and offset the overlappingstrapping portion and encircling sleeve.

'7. In a tool for producing a'joint between overlapping portions ofmetallic strapping and an encircling metallic reinforcing sleeve, havinga pair of spaced side plates, a pair ofpivot pins held by and bridgingbetween said side plates, a pair of folding jaws, each jaw beingpivotally mounted on one of said pivot'pins, said jaw having confrontinghook-like tips which approach each other to clamp the strap portions andsleeve when said jaws are oppositely rocked about said pins, anoperating linkage pivotally connected to said jaws for rocking said jawsabout said pivot pins, and means holding said side plates in place, theimprovement which comprises a pair of shearing and offsetting blades,each blade being loosely mounted on one of said pins by means of anopening therein substantially larger than said pin so that said bladeand said jaw mounted on said same pin may move relative to'each other, ablade actuating means on said linkage means, cooperat- References Citedin the file of this patent UNITED STATES PATENTS Number Name Date1,793,990 Bayer Feb. 24, 1931 1,893,901 McGregor Jan. 10, 1933 1,924,845Edwards Aug. 29, 1933 1,974,913 Childress Sept. 25, 1934 2,216,579Adamso-n Oct. 1, 1940 2,315,596 Childress Apr. 6, 1943

